One of the advantages of service robots is that they can do the dull and dirty jobs in human facilities, such as homes, commercial and industrial buildings, and institutions. However, that very action of robotic service itself may be unpleasant, inconvenient, disruptive, or even dangerous to a human that comes into proximity of the working robot.
Previous service robots have ignored this problem. As an example, current robot cleaners blithely treat humans the same way they treat the leg of a stool; usually by bumping into it, going around, it and continuing their work.
Although some robots built for human interaction have included the ability to recognize humans in their proximity, to date this has been used to further the interaction itself, but not to further a distinct service agenda.